Wastewater treatment systems are designed to remove contaminants from wastewater. For many years, many wastewater treatment systems have been designed for biological treatment. For example, biological treatment is utilized to remove BOD from the wastewater. Another example of biological treatment involves removing ammonia from wastewater. This is referred to as nitrification and denitrification. Another example of biological treatment is the use of microorganisms to remove phosphorus from wastewater.
More particularly, biological organisms or microbes generally extant in wastewater can be stimulated to perform wastewater treatment processes by consuming waste materials, and in some cases, producing other materials or compounds that are acceptable, or that can be subsequently removed from the wastewater.
Generally, sustained activation of microbial populations in wastewater requires oxygen, in that most of the organisms are aerobic in nature. Commonly, oxygen is provided by aerating the wastewater. Aeration may be done in various ways. However, typical approaches to aeration can be costly in terms of the energy required to operate pumps, compressors, agitators, stirrers, and the like. Minimizing energy costs is a major factor in the operation of wastewater treatment plants, and aeration costs can be a major part of total wastewater treatment plant energy costs.
There has been and continues to be a need for biological wastewater treatment systems and processes that control aeration and provide for an efficient cost-effective means for biologically treating wastewater.